But Enmity has never really been a thing tanks do. Going through the expansions, ARR, whilst the game was still young, you saw more tank stances, so it really wasn't an issue, however, even later on when top groups were starting to tank with DPS stance, the highest damage rotation included enmity generators. PLD only had the 1 combo and on WAR Butcher's Block was stronger and generated enmity.

Going into HW, WAR was the best tank, no questions, and it had no problems with enmity. Between Defiance + Unchained and it's absurd damage in Deliverance, it produced DPS levels of damage so it could easily keep up with enmity management. PLD had Savage blade and Shield Swipe (as an oGCD at this point) which generated enmity in their DPS rotation, which could easily keep up and DRK was the one that was left out, but generate a sufficient amount of enmity at the start of a fight, drop Grit and you are good to go. Helps that Darkside helped to mitigate the damage loss from Grit.

Stormblood, enmity was managed by the DPS, Diversion and Lucid Dreaming were the main enmity dropping tools and you were expected to use them. If you didn't the tank had to go into DPS stance and/or use their enmity combo. Which created a cascade of problems not only with lower damage from tanks but they also suffered in their resource generation, which leads to an even bigger loss. But whose fault was it when tanks didn't hold enmity? That's right, the healers and DPS for being lazy and not pressing that 1 extra button. It really wasn't a tank mechanic.

Then from then on, it is as we have it now.

At no point did the tank have a responsibility for specifically going after enmity generation past the initial enmity grab. It was always there as part of the DPS rotation or it was down to another role.

As for enmity generation (when it comes to damage), it is as simple as, the damage you do = the enmity it generates. This would have been why it seemed Trick attack boosted enmity generation, as it boosted damage, so more enmity generated.

As for enmity combos, how do you really plan to implement them? If they are a damage loss, everyone is going to avoid using them at all costs, especially if they halt resource generation. Imagine if a PLD in it's current state had to use it's enmity combo, but it didn't generate the Sword Oath combo or Divine Might after it. You can say, OK, add it onto the enmity combo then. You then end up with 2 combos where one does more damage but lower enmity generation and one does less damage but higher enmity generation. If we want to start talking about button bloat, this is one of the first places I would personally look. Not to mention current PLD only uses their basic 123 combo at most 3 times in a 60 second period, which would suck if you had to generate more enmity and restart the combo because you had it primed or you had to overwrite other buffs just for the enmity generation. That is just bad design.

Even looking at how you would display enmity, the longer a fight goes on, the harder it is going to be to show how much of a lead you have and as a result, how much you can get away with doing more damage, which leaves your rotation down to pure chance if you want to dance on the edge of what you can get away with or you play it extra safe and do less damage as a result. I could also see this leading to someone creating a 3rd party tool that gives a better idea of the enmity leads you have.

this is before we go into other factors that I have gone into great depth in the past. Enmity is not a good system. If you want to make tanks more interesting, you need to look at other things.